From: Andrew Jones <drjones@redhat.com>
To: Marc Zyngier <maz@kernel.org>
Cc: kvm@vger.kernel.org, qemu-devel@nongnu.org,
kernel-team@android.com, kvmarm@lists.cs.columbia.edu
Subject: Re: [PATCH 1/3] hw/arm/virt: KVM: Probe for KVM_CAP_ARM_VM_IPA_SIZE when creating scratch VM
Date: Mon, 23 Aug 2021 11:07:52 +0200 [thread overview]
Message-ID: <20210823090752.nanm4wttyefg3txh@gator.home> (raw)
In-Reply-To: <20210822144441.1290891-2-maz@kernel.org>
On Sun, Aug 22, 2021 at 03:44:39PM +0100, Marc Zyngier wrote:
> Although we probe for the IPA limits imposed by KVM (and the hardware)
> when computing the memory map, we still use the old style '0' when
> creating a scratch VM in kvm_arm_create_scratch_host_vcpu().
>
> On systems that are severely IPA challenged (such as the Apple M1),
> this results in a failure as KVM cannot use the default 40bit that
> '0' represents.
>
> Instead, probe for the extension and use the reported IPA limit
> if available.
>
> Cc: Andrew Jones <drjones@redhat.com>
> Cc: Eric Auger <eric.auger@redhat.com>
> Cc: Peter Maydell <peter.maydell@linaro.org>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> ---
> target/arm/kvm.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/target/arm/kvm.c b/target/arm/kvm.c
> index d8381ba224..cc3371a99b 100644
> --- a/target/arm/kvm.c
> +++ b/target/arm/kvm.c
> @@ -70,12 +70,17 @@ bool kvm_arm_create_scratch_host_vcpu(const uint32_t *cpus_to_try,
> struct kvm_vcpu_init *init)
> {
> int ret = 0, kvmfd = -1, vmfd = -1, cpufd = -1;
> + int max_vm_pa_size;
>
> kvmfd = qemu_open_old("/dev/kvm", O_RDWR);
> if (kvmfd < 0) {
> goto err;
> }
> - vmfd = ioctl(kvmfd, KVM_CREATE_VM, 0);
> + max_vm_pa_size = ioctl(kvmfd, KVM_CHECK_EXTENSION, KVM_CAP_ARM_VM_IPA_SIZE);
> + if (max_vm_pa_size < 0) {
> + max_vm_pa_size = 0;
> + }
> + vmfd = ioctl(kvmfd, KVM_CREATE_VM, max_vm_pa_size);
> if (vmfd < 0) {
> goto err;
> }
> --
> 2.30.2
>
Reviewed-by: Andrew Jones <drjones@redhat.com>
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next prev parent reply other threads:[~2021-08-23 9:08 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-22 14:44 [PATCH 0/3] target/arm: Reduced-IPA space and highmem=off fixes Marc Zyngier
2021-08-22 14:44 ` [PATCH 1/3] hw/arm/virt: KVM: Probe for KVM_CAP_ARM_VM_IPA_SIZE when creating scratch VM Marc Zyngier
2021-08-23 9:07 ` Andrew Jones [this message]
2021-09-08 7:16 ` Eric Auger
2021-08-22 14:44 ` [PATCH 2/3] hw/arm/virt: Honor highmem setting when computing highest_gpa Marc Zyngier
2021-09-07 12:58 ` Peter Maydell
2021-09-08 7:16 ` Eric Auger
2021-08-22 14:44 ` [PATCH 3/3] docs/system/arm/virt: Fix documentation for the 'highmem' option Marc Zyngier
2021-09-07 12:51 ` Peter Maydell
2021-09-07 17:09 ` Marc Zyngier
2021-09-07 18:25 ` Peter Maydell
2021-09-08 9:16 ` Marc Zyngier
2021-09-08 8:53 ` Eric Auger
2021-08-22 14:48 ` [PATCH 0/3] target/arm: Reduced-IPA space and highmem=off fixes Marc Zyngier
2021-09-07 12:52 ` Peter Maydell
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